干旱区生态环境知识资源中心

After model-based OPC and layer generation, the size of mask data is increasing beyond the limit that current software and hardware can handle. The file size of one of 512M DRAM mask data was 29 GB in GDSII and it could be reduced to 1.7 GB by transforming into OASIS. Compared to GDSII, OASIS included many effective features that could reduce the file size incredibly. In this paper, we adopted the repetitions in OASIS and used the concept to reduce the memory usage of mask data preparation software. We built a new data structure, called shape array that utilizes the repetition of mask data. Mask data is saved in OASIS and its repetition information is loaded onto memory. The data structure can be the basis for the mask data preparation operations such as region query, AND, XOR and so on. We implemented the region query in this paper. The region query is a major operation that a layout viewer uses. The mask data comparison operation, which is used to check the integrity of the mask data, is implemented with the shape array as well. The shape array method has used the memory of between 2 and 22 times less than the method that keeps the coordinate and attributes of each shape individually. The file loading time and the file writing time have improved 4 similar to 73 times and 1.5 similar to 14 times, respectively.